title: Impact of the BDNF Val66Met Polymorphism on Regional Brain Gray Matter Volumes: Relevance to the Stress Response.
abstract: OBJECTIVE
  Genetic imaging is used to investigate the mechanism by which genetic variants influence brain structure. In a previous study, a structural change of the dorsolateral prefrontal cortex was associated with symptom modulation in post-traumatic stress disorder patients. This study examined the effect of a polymorphism in the gene encoding brain-derived neurotrophic factor (BDNF) on regional gray matter (GM) volumes and the correlations between the dorsolateral prefrontal GM volume and the stress level in healthy volunteers.
  
  
  METHODS
  Sixty-one volunteers underwent genotyping for the BDNF Val66Met single nucleotide polymorphism (SNP) and completed the Stress Response Inventory (SRI). Magnetic resonance images were also acquired, and the effect of each subject's BDNF genotype and SRI subscore on his or her dorsolateral prefrontal GM volume was evaluated.
  
  
  RESULTS
  The Val/Val homozygotes had significantly larger GM volumes in the prefrontal cortex and the precuneus, the uncus, and the superior temporal and occipital cortices than Met carriers. The Met homozygotes demonstrated a higher stress response in depression domain than Val/Val and Val/Met groups. A negative correlation between the middle frontal cortex GM volume and the SRI depression subscore was found.
  
  
  CONCLUSIONS
  These findings indicate an interaction between genes and brain structure, and they suggest that differences in dorsolateral prefrontal GM volume related to the BDNF Val66Met SNP are associated with resilience to stressful life events, particularly in the dimension of emotion.
authors.affiliation: Department of Psychiatry, Seoul National University College of Medicine, Seoul, Republic of Korea. ; Institute of Human Behavioral Medicine, SNU-MRC, Seoul, Republic of Korea.
authors.forename: Sung Nyun
authors.initials: SN
authors.lastname: Kim
authors.forename: Do-Hyung
authors.initials: DH
authors.lastname: Kang
authors.forename: Je-Yeon
authors.initials: JY
authors.lastname: Yun
authors.forename: Tae Young
authors.initials: TY
authors.lastname: Lee
authors.forename: Wi Hoon
authors.initials: WH
authors.lastname: Jung
authors.forename: Joon Hwan
authors.initials: JH
authors.lastname: Jang
authors.forename: Jun Soo
authors.initials: JS
authors.lastname: Kwon
keywords: Brain-derived neurotrophic factor; Dorsolateral prefrontal cortex; Genetic polymorphism; Magnetic resonance imaging; Stress; Val66Met